But last week, at the behest of the cable and telephone industry, Senate Republicans voted along party lines to abolish those rules. If the House votes the same way the Senate did this Tuesday, the consequences for Americans’ privacy online will be disastrous. ISPs will be able to spy on web browsing, install spyware on phones, and sell data to advertisers—all without customers’ permission. Here are just a few of the potential consequences for Americans if they don’t stop Congress now:

ISPs could sell your data to marketers

It’s no secret that many ISPs think they’re sitting on a gold mine of user data that they want to sell to marketers. What some people don’t realize is that some are already doing it while the law is unclear on the legality of the practice. However, they’ll be forced to stop if the Obama-era FCC consumer protections go into effect.

According to Ad Age, SAP sells a service called Consumer Insights 365, which “ingests regularly updated data representing as many as 300 cellphone events per day for each of the 20 million to 25 million mobile subscribers” whose data is fed into SAP’s service. Who is selling SAP their customers’ data? Ad Age says “SAP won’t disclose the carriers providing this data.”

In other words, mobile broadband providers are too afraid to tell you, their customers, that they’re selling data about your location, demographics, and browsing history. Maybe that’s because it’s an incredibly creepy thing to do, and these ISPs don’t want to get caught red-handed.

AT&T did this despite having a legal duty to protect your confidential information under Section 222(a) of the Telecommunications Act. The company only discontinued the program last September, shortly before the FCC passed its privacy rules. If the House succeeds in repealing the FCC’s rules, you can be sure that pay-for-privacy plans like this will start popping up all over.

Remember, these companies carry all of your Internet traffic and can examine each packet in detail to build up a profile on you, which they can then use to inject even more ads into your browsing experience.

Simply put, preinstalled software like Carrier IQ gives your ISP a window into everything you do on your phone. While mobile ISPs may have backed down on using Carrier IQ in the past (and the situation led to a class action lawsuit), you can bet that if the FCC’s privacy rules are rolled back, there’ll be ISPs be eager to try something similar.

But it gets worse. Initially, there was no way for customers to turn this “feature” off. It didn’t matter if you were browsing in Incognito mode, using a tracker-blocker, or had enabled the browser’s “Do Not Track” feature: Verizon ignored all this and inserted their tracking tags anyway. As a result, anyone—not just advertisers—could track you as you browsed the web. Even if you cleared your cookies, advertisers could use Verizon’s tracking tag to resurrect them, which led to something called “zombie cookies.” If that doesn’t sound creepy, we don’t know what does.

The good news is that Americans can keep all of these practices from coming back from the grave. They just need to raise their voices and tell Congress that they value their legal right to privacy—and that they won’t sit idly by while Comcast, AT&T, Verizon, and others try to erase a monumental victory for consumers’ online privacy rights.